Conventional decks typically include horizontal floors raised above the ground and supported by an underlying structure. Decks are often attached to adjacent residential or commercial buildings. Deck boards are placed side by side during construction of a deck, and are typically arranged to cross the structures, such as joints at an angle perpendicular to the longitudinal axis of the joist. Other structures utilizing similar flooring techniques include boat docks, ramps, stairs, landings, bridges, platforms and for structures for surrounding or enclosing swimming pools and hot tubs.
Typically, decks are constructed to withstand exposure to the elements and are often constructed from pressure treated wood, plastic or, more recently, exotic hardwoods. Whether the deck boards, which form the flooring of the deck, are comprised of wood or plastic or other material, the substructure is typically formed of commonly available pressure treated lumber. The substructure is formed with joists and headers attached to posts. The deck boards are typically fixed transversely across the joists to the substructure, in a generally parallel relationship, by way of nails or screws, driven through the upper surface of the deck board into the joist below.
This manner of attaching deck boards to the substructure presents several disadvantages. If nails or screws are used, they typically cause discoloration of the surrounding wood surface over time. In addition, in driving the nail through the wood or plastic deck board, the surface of the board is often marred during hammering, causing unsightly dents and scratches to the top surface of the board. Both the discoloration of the wood and marring of the surface are of particular concern when exotic hardwoods are used.
In addition, nails have a tendency to work themselves loose from the board over time, projecting upward from the board's surface. Not only is this aesthetically unpleasing, it causes the deck board to loosen against the joist and also constitutes a safety hazard, particularly to individuals walking over the deck surface barefoot. In addition, both nails and screws are prone to rusting over time, causing failure to the attachment. Removal of one or more deck boards entails prying the nails loose which is both time consuming and causes damage to the surface of the board.
Since decks are constantly exposed to outside environmental conditions, the deck boards are exposed to extremes of both temperature and humidity. Both plastic and wooden deck boards will shrink and expand in response to temperature changes, and wooden deck boards will also shrink and expand as the moisture content of the board increases or decreases. Deficiencies in the attachment means in the prior art often cause attachment devices to loosen over time or to cause the deck boards to warp or crack because the attachment device does not provide for movement along with the board as it expands or contracts.